When artist Ann Hamilton completed building what she called an acoustic tower in Sonoma County last year, Meredith Monk was on hand for the inauguration. She sent up the tower's central spiral staircase vocalists, a string quartet, a woodwind player and a percussionist, singing and playing as they slowly ascended, their sounds reverberating in the eight-story silo and producing what one imagines to have been a magical, site-specific "Climb Every Mountain" of modern art.

That Hamilton tower is the DNA of "Songs of Ascension." The work is billed as a collaboration between a composer/choreographer/theater artist and a visual artist. But at REDCAT on Wednesday night, the only physical evidence of Hamilton's involvement was a video projection of murky images revolving around the theater. Essentially this is a major Monk work. Music is its center. The tower is left to the imagination, even though the use of space is still a significant aspect of the piece.

Workshopped at the Walker Art Center in Minneapolis, premiered at Stanford University earlier this month and intended for the Brooklyn Academy of Music's Next Wave Festival in fall 2009, "Songs of Ascension" felt particularly well suited Wednesday for the intimate, flexible REDCAT. The performance began with a lamp swaying back and forth over the stage while a chorus -- drawn from CalArts, one of the work's sponsors -- droned in surround sound, the singers placed in nooks between the acoustical tiles that line the walls of the black box. An electronic squeal here, some clattery percussion there, dissuaded the ear from an impression of anything New Age-y.

What happened for the next 70 minutes proved just the other side of understandable. Neither music nor movement was exactly ascensional. Instead, the feeling was more preparation for ascent at, say, an Everest base camp. No one seemed quite acclimated to the altitude, so things got a little strange.

Monk's music and movement are one process. Her use of extended vocal techniques is not so much the invention of new sounds as a means of extending the voice into the rest of the body. All those breathy ha-ha-has and hee-hee-hees are as much physical gestures as they are musical ones.

Pure movement in "Songs of Ascension" is of two types. The performers continually found new configurations onstage, which meant a mobile string quartet (the cellist raised her peg so she too could be part of this irregular marching band). There were also dance solos made of twitching motions. The first twitches came from Ellen Fisher, a member of Monk's outstanding six-member ensemble, who erratically flashed semaphore signals, as if summoning climbers. At evening's end, Todd Reynolds (the leader of the Todd Reynolds Quartet) played his violin lying flat on his back, which was, as far as I know, a first.

Hamilton's revolving video projections included a large roving eye as well as a horse and rider in silhouette and a man in motion. They evoked nothing in particular but filled the space with an apt odd aura.

The music was glorious. Monk's most significant growth over the past decade or two has been as a composer. Her movement and theatrical ideas, however engaging, don't surprise nearly as much anymore as her music does. She's still the ultimate Minimalist, putting a few notes together in limited rhythmic and contrapuntal combinations. But she is a great master of utterance. A singer can chirp a few flamboyant high notes and a listener feels not as if listening to bird-like song but somehow in communication with another, perhaps wiser, species.

The quartet music was simple too, but mesmerizing. String instruments were made to sound like voices, just as voices were made to sound like string instruments. And to prove the unity point, one member of Monk's ensemble, Allison Sniffin, both played violin and sang. Flexing the arms and the vocal cords became a single gesture.

Ascension itself was only alluded to. Sung sliding tones and glissandos played by the string quartet tumbled and tumbled some more, like sound descending from great heights.

At the end, Monk turned to a more traditional technique for producing the sense of looking heavenward -- a catchy repeated four-note rising scale in the quartet. The performers enacted a lavish processional. Singers riffed on and around the ascending motif. John Hollenbeck banged percussion attached to his body. Bohdan Hilash provided sonic depth on the bass clarinet. The chorus, in its cubicles, added more layers of joyful counterpoint.

Activity ceased with everyone lying on the floor for lights out, ready for the ascent. When the lights came back on, I expected to see the mountain.